In the related art, games are known in which the image of a part of a user's body such as a head is captured by a video camera, in which a predetermined area for an eye, a mouth, a hand, or the like is then extracted, and in which the area is replaced with another image for display on a display (for example, patent document No. 1). A user interface is also known that receives, as an instruction for operating an application, the movement of a mouth or a hand captured by a video camera.    [patent document No. 1] European Patent Application No. 0999518
In a technique such as the one described above, a high-resolution image is necessary for extracting a predetermined area for a user's mouth, hand, or the like. However, as the performance of an imaging element of a video camera becomes higher, it takes longer for performing a compression process when the video camera transmits an image to a host such as a game device or a personal computer after the compression. Therefore, there is a problem where latency between image capturing by the camera and video outputting by the host is increased. The use of the camera as a user interface creates a problem where an increase in the latency dramatically reduces usability. As described, even when the performance of an imaging element of a video camera is increased, the performance of a system as a whole may be reduced.